The present invention generally relates to compound semiconductor devices and more particularly to a high power compound semiconductor device that uses a nitride semiconductor of GaN or a nitride semiconductor containing GaN as the major component for the electron channel layer.
GaN has a large bandgap of 3.4 eV and is used conventionally for blue light-emitting diodes and laser diodes. On the other hand, in view of its large breakdown voltage and large saturation electron velocity, GaN is thought as a highly promising material for the semiconductor devices required to perform high voltage operation or high output operation. Thus, intensive investigations are being made for the FETs such as HEMT that uses GaN for the electron channel layer. Particularly, by using a high-voltage HEMT having an electron channel layer of GaN for the amplifier, it is expected that a high efficiency operation is attained.
Patent Reference 1
Japanese Laid-Open Patent Application 2000-252458
Patent Reference 2
Japanese Patent Application 2002-500626
Patent Reference 3
Japanese Laid-Open Patent Application 2003-535481
Non-Patent Reference 1
H. Kawai et al., Electronics Letters 19 Mar. 1998, Vol. 34, No. 6, pp. 592-593
Non-Patent Reference 2
J. Nikaido, et al., A Highly Uniform and Reliable AlGaN/GaN HEMT, www.gaasmantech.org/Digests 2005/2005 papers 8.1 pdf (search made on Jun. 21, 2007)